Secondary battery.



W. MORRISON.

SEGNDARY BATTERY.

APPLICATION FILED JUNE a, 190s.

940,043. Patented N0v.16,19o9

WILLIAM MORRISON, OF CHICAGO, ILLINOIS.

SECONDARY BATTERY.

Specification of Letters Patent.

Patented Nov. 16. 1909.

Application led June 8, 1903,. Serial No. 160,647.

To all 'whom 'it may concern:

Be it known that I, lVILLiAn Monmsoxa citizen of the. United States of America, andl resident of Chicago, Cook county, Illinois,I

`have invented a certain new and useful Improvement in Secondary Batteries, of which the following is a specification.

My invention relates to a certain improvement in connection with that type ot elecfio trical reversible galvanic battery in which there is an alkaline solution and zinc is one of the active elements. The improvement which I herein describe and claim is a part Aof the construction preferably employed by me in a battery of this type which I have broadly claimed in an application tiled by me concurr xntly herewith and designated as Serial Number 160,645.

The object of my invention herein claimed is to provide an electrode support, which is capable of receiving and holding the active element of Zinc and the amalgam therefor, in such a way as to preserve the support in a condition to properly receive and hold the zinc. and also whereby the zinc when deposited from the solution is in a practically fresh'aud clean state.

My present invention, as stated, is to be used in connection with that type of battery in which there is an alkaline lsolution together with a negative electrode the active element of which is zinc, disposed substantially horizontal. in the bottom of the cell, which cell preferably made of metal. This negative electrode, as shown and described herein, is constituted of a number of screens made of woveirwire and superimposed one upon the other. After having been treated, in a manner to be described, these screens. which may be tightly and firmly bound together by sewing or soldering may be soldered tightly to the bottom of the cell. When thus in place within the. cell an electrode supportis provided which presents a porous roughened surface with openings therein permitting the penetration of the '/.nc and of the mercury which is used,

to ainalgamate the zinc, in the manner to be described. The binding together of the vai rious screens to form the electrode support or bed. and the fastening ot' the said support t the cell itself on the bottom vides a support having a maximum con ductivity and in iutimate'contact With the cell itself.

Figure l is a cross-sectional `view of the thereof prof' ,',coinplete cell.

the

'electrode H is placed Fig. 2 is a perspective View electrode support. Fig. 3 is a detail view partly in cross-section- In carrying out my invention. and as con stituting one specific Iembodiment thereof. l provide preferably a metal cell A which may be of copper, iron, steel, or other suitable metal. within which l build up one upon the other in the bottom of the cell, a number of screens of woven wire or perforated metal. designed at B. These screens, which are preferably of copper. are l'neliminarily treated by plating them with silver. copper or other suitable metal, to form a metallic spongv and porous covering capable of1 absorbing vand holding a large quantity of mercury. l then .till the4 spongy porous covering with mercury by dipping the screens into a vat of cyanid of mercury and then again into a vat of metallic mercury. Care, however. should be taken to wash out the c vanid. These screens are then electroplated in a solution of caustic potash, having` zincY dissolved therein, untilY a necessary quantity of zinc is deposited upon the screens. rThe screens so prepared are then deposited one upon the other in the bottom of the cell. which cell has been previously plated and ainalgamated on the bottom. (Fig. 3.) A suflicient number of these screens are so disposed to form a negative electrode (l. of sufficient thickness or depth. Above this negative electrode is an insulat` ing band D. l provide a grid-shaped protecting member E, of insulating material, having cells(- passing through it from to "to bottom. Upon the top of this member E the negative electrode H of aluminuimcopper, silver, nickel, or other suitable material, of the character used in the well-known types of alkaline batteries. It. shouldbd, prefer-- ably perforated. or so constructed,1 to permit the gas to pass above the positive electrode and permit the free circulation of the liquid.

The insulating protector E is placed upon the top of the negative electrode and Within the outer insulating band D. Thepositive upon the top of the insulating protector C, and a second inner and insulating band J extending completely about the interior of the cell and resting against thev outer insulating band D, rests. at its lower edge, upon the marginal edge of the positive electrode. The cover D2 Sets Within thelcell A and bears upon the upper roo ilo

electro-plating between insoluble electrodes,l 30.

cell itsel edges of the two insulating bands 'eiid J, so that when the cover is pressed downwardly and soldered outer insulating band presses the marginal edges of the negative electrode firmly into place and the inner insulating band J pressing downward upon the positive electrode in turn causes the insulating protector E firmly press u neatli, thus binding the various screens of the v ositive electrode irml the ottom of the coll. l these various screens/may be sewed together or soldered, or otherwise fastened to ether, and the electrode support soldered to t itself, thus giving a greater amount of con ductivity to the electrode su port and more intimate contact with the ce itself.

A 'conductor a 'extends to and is 'connected with a binding Apost b which extends through the cover and is isolated therefrom andl fastened thereto by insulating plates'so secured in place as to prevent leakage. The other binding 1post d is fastened to the lmetallic The solution n'iaybe otcaustic potash or caustic soda, although 'I' prefer the former. I prefer to purify the caustic potash by vWith a suitable electric current, until the greater ortion of the sediment is deposited on the e ectrodes or precipitated.

cient number to provide a The negative electrode support consists of a number of wire screens, previously described, placed one upon the other in a suilif oi'ous, open and conducting bed or receptac e for the reception of a sufficient quantity of zinctto give the desired discharge. The zinc is deposited upon the u per screens, or may be de os'ited on all of t e screens, the screens wit their openii' s permitting the residuum produ trode 'and maintain the greater art of the Vactive-zinc portion of theelectro e upon the In the operation' of the battery, and in the rst charge, the zinchaving been previously electro-deposited, 'h drogen'is liberated and the positive electro knownmanner. the` discharge,I the zinc is dissolved .into the solution andthe positive electrode is 'reduced' in the well-knowirinan ner; Ifthe 4electrodes 'are of greater'ca-- acity than the solution employed, the so-l .utionwil'ldissolve and'take u the zinc to its ultimate capacity and then ,t ey remainder of the zinc will be oxidized in the further 'continued discharge and consequent generaiim': :if current, lthis portion of the yzinc remanin as an oxid of zinc in the negative electro e. And itis apparent that the positive electrode'will' be still further reduced. It isI also apparent thatv as the solution gradually loses its capacity to re-dissolve and in place firmly the t0.. on the negative electrode betogether and to' found desirable,

e' cell' 'a si fiicienit mesh or foreign' ts to penetrate farther into the elec-ji e is oxidized inthe welltake up the zinc,"'th'e 'quantit of okid of zinc in the negative electrode will graduallyin crease in -the continued operation of the battery. ,In the second charge the zinc in the solution is first deposited upon the negative lelectrode in the forni. of metallic zinc and `vrthere/the liberated hydrogen reduces-the oxid of zinc in tlienegative electrode to nietallic zinc, the positive electrode being oxidized. 'In the further successive charges and discharges, as the solution loses its capacity to re-dissolve the zinc, more and inore of theoiid of zinc remains inand upon the negativev electrode'. ,A l

ln my i'eryearly experiments, on my presenttype of'ba.ttery,1 deposited'zinc upon the bottom of a metal cell,'but ll found that the movements of thebattery, such :is it would receive in automobile Work, would cause the solution towash over the zinc fand detach a part of it roindtssupport and wash it to oneside of the cell where it would shortcircuit the electrodes. This action would be facilitated byfnot charging the battery at the'pro'per rate, as the zinc would be spongy and loose andthu's more readily detached and shifted. I then tried one screen resting upon and held against the bottom cell. but soon lfound thatalthough the zinc bound itself into andaround the screen, a sediment deposited the solution, and possibly from thel Apositive electrode, settled upon the top ofV the screen, forming a coating which preventy ed the necessary. adherence and ensity of the zinc deposit, and this led to the provision 'of a number of screens which` Aprovided a' bedto hold the zinc and permit the sediment eiietrate' farther into the electrode suppor Therefore, in selecting these screens, car(l should be takento select. a vscreen with y toprovide'free openings for the sediment and at the Sametime hold the zinc, By this means zinc lwas kept clean and practically free from foreign sediment,` and .washeld in place perinitting'free circulation o in the discharge the zin is taken up into the solutiontlie sediment settles vfarther toward the bottom of the cell, andffiii the chargel fresh and `cleaii"zinc is,deposited..

coinp'rativelyfee from sediment, on the top of the electrode.' The'c'ontinuedcharge and discharge assist the natural tendency toward a settlement of the sediment farther into the electrode lea'v'iiig the top portion of the electrode comparatively free from sediment vand in conditioii'to 'receive the-zinc. This screen formation'als'o, by reasonot its mesh, to 'prevent the sediment from 'being Washed out of thel screen intol the solution.

' The ne ative electrode is thoroughlyv amalgamated efore being placed in the cell, and this amalgam is reserved in each successive charge by provi ingan excess of mercury' in the bottom of the cell. It .is advisable to 'the solution. in;

ico

I" foundl that the i ric tends ist" bimi4 the screens 'tigliiv together and to the botmu of the cell so lia; tlieiieroury muy :freely find ite my from one Screen to iii-3 oher aud 'illus muiuain iiorougii and'com'- plete uimilgg'eirvzitioriq l 'found that uncierl liu reflueiiig aerien of the charge die alive" eleorode, ihre. mercury adheres and binde 'with u lurge proporion of Sedimeur. and alero with the eleoirode iself, maintainv ing a liorouglx uinalgmiiaiiou for the recepi iiou of the deposired zine und to preveni i loi-.al uctiou. This thorough mnzligamation i is mafie possibie bj.' reason of the location of lie elocirorle in 'he botom o ihe cell in subsiuutiallv horizontal poeitioii, ami or g the porous nature of ille salue. This is ovi- 1 deut because* the mercury may disiribute l iielf ilirougli the eieoiroie, and cannot fall oil' from the electrode. The mercury is l always iu cour-et xviih the elecimde.

".Ylmi i claim as my invention is:

i, in au electric reversible gaivzmic battery iu wliieli There .is n Suinble alkfiiine sointimi uml ziuo is ille active elemeui, a support or grid therefor iomprising a pluraiit f l of superimposed screens @f woven Wire sel cured together euri disposed ink :i substmi i t-i-ally horizontal posiioi at or naar the iiotl tom of the cell, Suid activeeierrxeu of Zinc l being elecirodleposiied ,downward in the dil rection of gravity in the Charge upon Suid 5 support or grid, togetiier xviii! e posiivei electrode above the negative. electrode. i

i2. In :iu 'electric reversible ggaivmio bet-l tary iii Whicl. there is a suiiuble alkaline sol lutiou and zinc is the aciive elemerir1 a Subi stautiallv horizogitul support or grid lierefor having openings or pores iherein couipris-ing a plurality oiE superimposed screens oi woven wire secured togeilier. :mi oxidli is or pores which is of zinc iu eziicl openiii reduced eleetricuily o meiullie zine in the charge, together 'ith u positive eleerofle above the negative eleo'rofle.

foi-ations or openings 3. in nu electric, reversibile ,qalvauio bei! said support or grid is substantially horizontaily disposecl,

iogeiier with u posirive eleotrode above the negative eleeroilo.

In mi electric reversibie galvui'iie bui.- iery in which iiiere is a snif-2eme alkaline sw lution and zinc is die active element, u nega tive support or ,f1-rid therefor having per- .iherein and dispo-seri in a substantially horizontal position et or near the botom of the Cell, .said aetive element of zinc being eleotro-epositfed down werd in the direction of grew/ity in the. charge upon said negative support or grid, together with a positive eiectrofle above the negtive electrode, the, zinc on Said :retire eiemeut being; in excess oi the capuoiy of said soluiion lo dissolve.

In an electric reversible galvsme. boery. in which there is an iiikaliiie electrolyte, :md zine is the active element, e, substantially horizontai negative suppori'J comprising zi plurality of superimposed screens of woven Wire secured together, anzi herring zinc de.- positeci thereon in Vexcess or the capacity of the electrolyte to dissolve whereby after "che electrolyte has to iis fuii capacity, rile balance of seid zinc is oxidized., together with e positive electrode above Seid negative eleororie.` e

'Signed by me at Chica-go, @ook county, illinois, this 6th dey of. gime, i903.

'Wiioesses Cime. fC., Bamm@ WM, A. Hmmm.

pl uraiiity dissolved all. of said zinc up 

